Generally, when one wants to prepare a beverage by infusion formed by mixing at least two products (for example, to prepare a cappuccino which, as well known consists of coffee and milk foam) is used a capsule or a chamber in which products are already mixed or a capsule in which are defined two chambers, one for each product and one overlapping the other. For the two chambered capsules in use hot water under pressure is channeled in the upper chamber so as to create a first infusion with the first product and then through the openings the first infusion is channeled towards the second chamber so as to mix with the second product to create the beverage. It seems obvious that if coffee and milk are used as products the outcoming beverage from the capsule is not a real cappuccino but rather a normal milk and coffee. In fact, a real cappuccino involves separate preparation of coffee and of a milk foam, which are then always poured separately in a cup.